Virtual Private Networks (VPNs) are used to interconnect geographically remote offices, campuses, factories, research labs and other factories of an Enterprise Across a shared network. This shared network may be a wide-area network (WAN) such as the Internet. The VPN may include a Multiservice Provisioning Platforms (MSPPs), a WAN router and a VPN-dedicated device at each geographic site. VPNs may utilize a Virtual Local Area Network (VLAN), a multiprotocol label switching (MPLS) over SONET network or other network.
VLANs group network—connected devices without relation to their physical wiring and constructions. The sending and receiving of frames is performed within the same group and the broadcasting of frames also takes place within the same group. Communication with a different VLAN group generally uses the intermediary of a router.
MPLS provides a virtual communication path in an Internet Protocol (IP WAN), which may include a SONET network. In particular, MPLS adds a label onto an IP packet that identifies a connection. The network router transmits the IP packet by popping, pushing or swapping the value of the label. In this way, an IP connection-type service is provided. However, the MPLS standards do not address integration of all aspects of MPLS switching into a SONET network.